Many cereals that appear to be healthy actually contain a lot of added sugar.

It's best to stick to cereals that have fewer than 7 grams of added sugar and more than 4 grams of fiber.

Raisin Bran surprisingly has 18 grams of sugar per serving while Lucky Charms only has 10 grams per serving.

Granola is a great option, but you should always check how much sugar is added.

Depending on the brand you purchase, cereal can be a quick, easy, and nutritious way to start the day off.

Many cereals, however, are packed with sugars and unhealthy ingredients, making them terrible additions to a well-balanced diet. It's vital to analyze your cereal options before purchasing to ensure you start off each day with a healthy bowl.

"Read the nutrition facts label and see how many grams of sugar is in a serving. A good rule of thumb is to pick cereals with less than 7 grams of added sugar per serving," Jennifer Bannigan a registered dietitian with Next Stage Nutrition told INSIDER.

"Remember this equation: four grams of sugar equals one teaspoon. If you eat one serving of a cereal with 17 grams of added sugars, that's eating over a tablespoon of added sugar alone. Added sugars provide no nutritional value and [are] commonly referred to as 'empty calories.'"

Bannigan advised consumers to stay away from cereals that contain high fructose corn syrup, corn syrup, or corn syrup solids. She also emphasized the importance of finding a cereal with fiber.

According to Bannigan, you should make sure that the cereal you eat has at least 4 grams of fiber. She says that fiber not only keeps you full, but is also good for your digestive system.

So which cereals are truly the worst for you when it comes to nutrition? Bannigan debunked how healthy — or unhealthy — these five common cereal brands are.

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Cheerios Protein Oats and Honey

You may think that you're being healthy by choosing a cereal that's packed with protein, but Cheerios Protein Oats and Honey flavor contains 17 grams of added sugar. A serving of 1.5 cups of the cereal with half a cup skim milk is 250 calories.

Cascadian Farm Organic French Vanilla Almond Granola

Granola can be tricky: It seems like a healthy option but, often times, it's full of added sugars. Two-thirds of a cup of Cascadian Farm Organic-French Vanilla Almond Granola contains 13 grams of sugar, 3 grams of fiber, and 240 calories. Although it certainly isn't the worst cereal option for you, it's far from the best.

"This cereal would be best added to low fat yogurt or sprinkled on top of mixed berries for those looking to manage their weight," Bannigan said.

Cap'n Crunch

Cap'n Crunch is, surprisingly, not a terrible cereal option. Each 3/4 cup serving of the brand contains 12 grams of sugar and 150 calories. The downfall, however, is in the fiber.

"This cereal has a better sugar choice for ingredients, but has less than one gram of fiber. Fiber adds to the feeling of fullness/satiety. The better option is to mix [it] in with a trail mix or have it as a dessert instead of a bowl of ice cream," Bannigan said.

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Lucky Charms

Each three-quarter cup serving of Lucky Charms with half a cup of skim milk is about 150 calories. And even though the cereal brand is well known for its bright colored marshmallows, there isn't too much added sugar: only 10 grams.

But with only 2 grams of fiber per serving, there are plenty of better options.

"Use this cereal as a treat, and not a breakfast staple," Bannigan told INSIDER.

Raisin Bran

Raisin Bran is a cereal that is, at first glance, seemingly healthy. You'd be shocked to hear how much sugar is packed in each box.

For every one cup serving, there are 18 grams of added sugar. On the flip side, there are also 7 grams of fiber in each serving.

"At first glance, 18 grams of sugar seems a bit high," Bannigan said. "This cereal has both natural sugar from the raisin and added sugars. The 7 grams of fiber will add to the feeling of fullness. Not the best option, but a better option for those who are looking to make a switch from Lucky Charms or Cap'n Crunch."

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